diff options
Diffstat (limited to 'dbutil.c')
| -rw-r--r-- | dbutil.c | 45 |
1 files changed, 43 insertions, 2 deletions
@@ -393,8 +393,7 @@ int connect_remote(const char* remotehost, const char* remoteport, * and the pid. exec_fn is the function that will actually execute the child process, * it will be run after the child has fork()ed, and is passed exec_data. */ int spawn_command(void(*exec_fn)(void *user_data), void *exec_data, - int *ret_writefd, int *ret_readfd, int *ret_errfd, pid_t *ret_pid) -{ + int *ret_writefd, int *ret_readfd, int *ret_errfd, pid_t *ret_pid) { int infds[2]; int outfds[2]; int errfds[2]; @@ -466,6 +465,48 @@ int spawn_command(void(*exec_fn)(void *user_data), void *exec_data, } } +/* Runs a command with "sh -c". Will close FDs (except stdin/stdout/stderr) and + * re-enabled SIGPIPE. If cmd is NULL, will run a login shell. + */ +void run_shell_command(const char* cmd, unsigned int maxfd, char* usershell) { + char * argv[4]; + char * baseshell = NULL; + unsigned int i; + + baseshell = basename(usershell); + + if (cmd != NULL) { + argv[0] = baseshell; + } else { + /* a login shell should be "-bash" for "/bin/bash" etc */ + int len = strlen(baseshell) + 2; /* 2 for "-" */ + argv[0] = (char*)m_malloc(len); + snprintf(argv[0], len, "-%s", baseshell); + } + + if (cmd != NULL) { + argv[1] = "-c"; + argv[2] = cmd; + argv[3] = NULL; + } else { + /* construct a shell of the form "-bash" etc */ + argv[1] = NULL; + } + + /* Re-enable SIGPIPE for the executed process */ + if (signal(SIGPIPE, SIG_DFL) == SIG_ERR) { + dropbear_exit("signal() error"); + } + + /* close file descriptors except stdin/stdout/stderr + * Need to be sure FDs are closed here to avoid reading files as root */ + for (i = 3; i <= maxfd; i++) { + m_close(i); + } + + execv(usershell, argv); +} + /* Return a string representation of the socket address passed. The return * value is allocated with malloc() */ unsigned char * getaddrstring(struct sockaddr_storage* addr, int withport) { |